STEVAL-CCA021V1 STMicroelectronics, STEVAL-CCA021V1 Datasheet - Page 28

• Manufacturer Part Number: STEVAL-CCA021V1
• Description: BOARD EVAL AUDIO FOR STM32F103
• Manufacturer: STMicroelectronics

Specifications of STEVAL-CCA021V1

• Amplifier Type: Class D
• Output Type: Mono jack connector, 2 terminal connectors, 2 RCA jacks
• Max Output Power X Channels @ Load: 2.2W x 1 or 2 @ 4 Ohm
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: STM32F103, TS4657(TS2012, TS4962, TS472)
• Description/function: Audio D/A
• Operating Supply Voltage: 3 V to 5.5 V
• Output Power: 2.8 W
• Product: Audio Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: TS4657
• Other names: 497-10338

Demonstration kit software
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General characteristics
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The aim of the PC demonstration kit application mode is to store the data (audio Stream)
received from the host PC in a specific buffer called Stream_Buffer and to use the I
peripheral to play it through external DAC afterwards.
As detailed before, the STM32F10xxx manages the isochronous data transfer using the
double buffer mode. So to copy the received data from the PMA to the Stream_Buff (using
DMA transfer), the swapping between the two PMA buffers (ENDP1_BUF0Addr and
ENDP1_BUF1Addr) has to be managed. Swapping access to the PMA is managed
according to the buffer usage between the USB-FS-device IP and the firmware. This
operation is provided by the EP1_OUT_Callback () function (usb_endp.c file). After the end
of the copy process, global variables called B0_Ready or B1_Ready are set.
To play back the audio samples received from the host is the I
Samples variable controls the streaming flow to synchronize the data from the USB-FS-
device with the Stream buffer used by the I
For further details on usage of USB-FS-device firmware library for Audio Device Class
purposes, please refer to UM0424, STM32F10xxx USB-FS-device development kit available
online from www.st.com.
Record-replay application
In the second mode of operation has the demonstration application task to capture vicinity
sound from embedded microphone, process simple normalization of the signal, store
acquired waveform into buffer in RAM (Record_Buff[]) in PCM16 format and finally play this
sample back through the same I
procedure is performed in a infinite loop till another mode is set by button press.
USB-FS-device characteristics:
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Audio characteristics:
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I
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2
S characteristics:
Endpoint 0: used to enumerate the device and to respond to class-specific
requests. The maximum packet size of this endpoint is 64 bytes.
Endpoint 1 (OUT): used to receive the audio stream from the PC host with
a maximum packet size up to 192 bytes.
Audio data format: type I / PCM format / stereo.
Audio data resolution: 16 bits.
Sample frequency: 48 kHz.
Channel frequency (also called LEFT/RIGHT clock) is 48 kHz
MCLK, the external master clock is 12.288 MHz
Packet frame is fixed to 16-bit
Data format is LSB-justified standard (Right-Justified)
Doc ID 15867 Rev 1
2
S mechanism like in previous application mode. This
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S peripheral.
2
S audio peripheral used. The
2
UM0722
S